Fire trap for internal-combustion engines



May 13, 1930. M. HEDGLON 1,758,442

FIRE T RA? FOR INTERNAL COMBUSTION ENGINES Filed Sept 27, 1928 INVENTOR.

A TTORNEYS I Patented May 13, 1930 Artur; oFFIcE MEAD HEDGLON, OF SYRACUSE, NEW YORK, ASSIGNOR TO M. L. OBERDORFER BRASS COMPANY, OF SYRACUSE, NEW YORK, A CORPORATION OF NEW YORK FIRE TRAP FOR INTERNAL-COMBUSTION ENGINES Application filed September 27, 1928. Serial No. 308,666.

This invention has for its Object, a fire trap for internal combustion engines which is particularly'simple and efiicient in construction and readily applied to the carburetor 5 of the engine and confines the backfire to the trap and hence, prevents the escape of back fire or of burning gases into the outer air.

The invention consists in the novel features and in the combinations and constructions l0 hereinafter set forth and claimed. In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure 1 is a diagrammatic view illustrating an internal combustion engine in side elevation provided with my invention. 7 Figure 2 is a lengthwise vertical sectional view through the air trap.

Figure 3 is an end View partly broken away.

This fire trap is particularly applicable for boat engines where the escape of back fire is likely to ignite grease, oil and gasoline in,

the engine pit.

1 designates an internal combustion engine and 2 any conventional type of carburetor having the usual main air intake 3, the carburetor having its outlet connected to the intake yoke 4 of the engine.

The fire trap is mounted on the air intake so that normally, the air passes through the trap into the carburetor, and consists of a plurality of screens arranged one withinv the 35 other and spaced apart forming a compartment between them.

1 As here illustrated, the trap comprises opposing heads 7 and 8 and concentrically arranged and spaced apart cylindrical screens 9, 10 and 11 interposed between the heads, the heads being held together and hence clamped on the ends of the screen by tie-rods 12. One head is provided with a hub 13 for connection to the air intake of the carburetor. The other head may be provided with a similar hub 14 for connection through a suitable pipe 15 to the interior of the crank case of the engine for the purpose of drawing off vapors from the crank case oil. However, the main supply of air enters the intake of the carburetor through the screens. 9, 10 and 11. f

The screens are preferably formed with onesixteenth inch holes and, ninety holes per square inch.. It is only necessary that the holes be small enough to prevent any flame from communicating through the holes to the outer-air.

In operation, when a back fire occurs, the

gas is blown back through the carburetor into the fire trap and there burns usually within the innermost screen 9, the screen preventing the flame from passing out to the outer air and igniting inflammable material. As the burning gas expands, it is forced through the screens one by one and by the time it has passed through. all the screens, it has expanded sufficiently so that it is cool enough to be harmless.

What I claim is:

1. The combination with an internal combustion engine having a carburetor provided with a main air intake, of a fire trap around the air intake and comprising a plurality of screens spaced apart, one outside the other forming an expansion and cooling chamber between the intake and the outer air for gases formed by the fuel ignited in the intake.

2. The combination with an internal combustion engine having a carburetor provided with a main air intake, of a fire trap around the air intake and comprising a plurality of screens spaced apart, one outside the other forming an expansion and cooling chamber between the intake and the outer air for gases formed by the fuel ignited in the intake, saidscreens and the expansion and cooling chamber formed thereby being located laterally relatively to the direction ofthe flow of airto the carburetor therethrough;

3. The combination with an internal combustion engine, having a carburetor provided on the air intake and the other of which is formed with an inlet opening for air and cylindrical screens located between the heads one within the other and spaced apart forming an expansion and cooling chamber for I the ignited gases burning Within the innermost screen.

In testimony'whereof, I have hereunto 5 signed my name, at Syracuse, in the county of Onefldal 5 mm State ozf New York; this 

